1,182 research outputs found

    Application of Lattice Boltzmann Method for Surface Runoff in Watershed

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    Derived from simplifications of the Saint-Venant equations, the kinematic wave model has the ability to describe the behavior of surface runoff in watersheds. This paper aims to obtain the numerical simulation of the flow routing in a natural watershed, by using lattice Boltzmann method. In the computational model, the surface of the basin will be represented by a V-shaped segmented in two lateral planes and one main channel. The simulation considers the effective precipitation flowing on the watershed per unit of width at the exit of each of the planes that represent the surface of the basin. The water flowing from the planes enters the main channel in the form of lateral contribution. Hydrograms of two rain events are obtained, which present the volume drained in the outlet corresponding to the whole basin in each event. Two equilibrium distribution functions were developed by Chapmann-Enskog expansion at time scales and model D1Q3, one suitable for flow on the basin surface and another for the main channel, in order to obtain the variables of interest in each case. The numerical results obtained were compared with the KINEROS2 hydrological model.Peer Reviewe

    A single trapped ion in a finite range trap

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    This paper presents a method to describe dynamics of an ion confined in a realistic finite range trap. We model this realistic potential with a solvable one and we obtain dynamical variables (raising and lowering operators) of this potential. We consider coherent interaction of this confined ion in a finite range trap and we show that its center-of-mass motion steady state is a special kind of nonlinear coherent states. Physical properties of this state and their dependence on the finite range of potential are studied

    Tamanho de amostra-referência para regressão múltipla em milho

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    The objective of this work was to determine the number of plants required to model corn grain yield (Y) as a function of ear length (X1) and ear diameter (X2), using the multiple regression model Y = β0 + β1X1 + β2X2. The Y, X1, and X2 traits were measured in 361, 373, and 416 plants, respectively, of single-, three-way, and double-cross hybrids in the 2008/2009 crop year; and in 1,777, 1,693, and 1,720 plants, respectively, of single-, three-way, and double-cross hybrids in the 2009/2010 crop year, totaling 6,340 plants. Descriptive statistics were calculated, and frequency histograms and scatterplots were created. The sample size (number of plants) for the estimate of the β0, β1, and β2 parameters, of the residual standard error, the coefficient of determination, the variance inflation factor, and the condition number between the explanatory traits of the model (X1 and X2) were determined by resampling with replacement. Measuring 260 plants is sufficient to adjust precise multiple regression models of corn grain yield as a function of ear length and ear diameter. The Y = -229.76 + 0.54X1 + 6.16X2 model is a reference for estimating corn grain yield.O objetivo deste trabalho foi determinar o número de plantas necessário para modelar a produtividade de grãos de milho (Y) em função do comprimento de espiga (X1) e do diâmetro de espiga (X2), por meio do modelo de regressão múltipla Y = β0 + β1X1 + β2X2. Os caracteres Y, X1 e X2 foram mensurados em 361, 373 e 416 plantas, respectivamente, de híbridos simples, triplo e duplo no ano agrícola 2008/2009; e em 1.777, 1.693 e 1.720 plantas, respectivamente, de híbridos simples, triplo e duplo no ano agrícola 2009/2010, tendo-se totalizado 6.340 plantas. Foram calculadas estatísticas descritivas, e confeccionados histogramas de frequência e diagramas de dispersão. O tamanho de amostra (número de plantas) para a estimação dos parâmetros β0, β1 e β2, do erro-padrão residual, do coeficiente de determinação, do fator de inflação da variância e do número de condição entre os caracteres explicativos do modelo (X1 e X2) foram determinados por reamostragem, com reposição. A mensuração de 260 plantas é suficiente para ajustar modelos de regressão múltipla precisos para produtividade de grãos de milho, em função do comprimento de espiga e do diâmetro de espiga. O modelo Y = -229,76 + 0,54X1 + 6,16X2 é referência para estimar a produtividade de grãos de milho

    Reactive Arthritis: From Clinical Features to Pathogenesis

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    Reactive arthritis (ReA) is a sterile synovitis which occurs after a gastrointestinal or urogenital infection. ReA belongs to pondyloarthritis (SpA), a group of diseases that share several clinical and radiological features including familiar clustering, absence of rheumatoid factor and association with HLA-B27. Clinically, ReA is characterized by an asymmetric arthritis predominantly affecting the lower limbs, often associated with urethritis, conjunctivitis and other extraarticular symptoms. The ReA prevalence depends on the incidence of causative pathogens. The ReA diagnosis is based on clinical features and serological tests to evidence previous infection. Different treatment including antibiotics, disease modifying antirheumatic drugs (DMARs) and biologic agents has been recommended. Even though knowing that infections trigger the joint inflammation, the ReA pathogenesis remains to be poorly understood. Several animal models and in vitro studies have been used to elucidate the mechanisms involved in ReA development. In this sense, HLA-B27 transgenic rat or mice have been used to explain the role of this molecule in SpA aetiopathogenesis. Moreover, the infectious model of Yersinia-induced ReA in rodents has shed some lights on the relationship between host genetic susceptibility to infection and abnormal immune response in ReA development. Understanding the immune mediators triggering ReA will contribute to find a specific treatment for this arthritis. In this review, we focus on clinical features, epidemiology, treatment, and the different attempts to understand the pathogenesis of ReA.Fil: Di Genaro, Maria Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto Multidisciplinario de Investigación Biológica de San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; ArgentinaFil: Cargnelutti, Ethelina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentin

    Language brain representation in bilinguals with different age of appropriation and proficiency of the second language: A meta-analysis of functional imaging studies

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    Language representation in the bilingual brain is the result of many factors, of which age of appropriation (AoA) and proficiency of the second language (L2) are probably the most studied. Many studies indeed compare early and late bilinguals, although it is not yet clear what the role of the so-called critical period in L2 appropriation is. In this study, we carried out coordinate-based meta-analyses to address this issue and to inspect the role of proficiency in addition to that of AoA. After the preliminary inspection of the early (also very early) and late bilinguals\u2019 language networks, we explored the specific activations associated with each language and compared them within and between the groups. Results confirmed that the L2 language brain representation was wider than that associated with L1. This was observed regardless of AoA, although differences were more relevant in the late bilinguals\u2019 group. In particular, L2 entailed a greater enrollment of the brain areas devoted to the executive functions, and this was also observed in proficient bilinguals. The early bilinguals displayed many activation clusters as well, which also included the areas involved in cognitive control. Interestingly, these regions activated even in L1 of both early and late bilingual groups, although less consistently. Overall, these findings suggest that bilinguals in general are constantly subjected to cognitive effort to monitor and regulate the language use, although early AoA and high proficiency are likely to reduce this

    How is anxiety related to math performance in young students? A longitudinal study of Grade 2 to Grade 3 children

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    Both general and math-specific anxiety are related to proficiency in mathematics. However, it is not clear when math anxiety arises in young children, nor how it relates to early math performance. This study therefore investigated the early association between math anxiety and math performance in Grades 2 and 3, by accounting for general anxiety and by further inspecting the prevalent directionality of the anxiety\u2013performance link. Results revealed that this link was significant in Grade 3, with a prevalent direction from math anxiety to performance, rather than the reverse. Longitudinal analyses also showed an indirect effect of math anxiety in Grade 2 on subsequent math performance in Grade 3. Overall, these findings highlight the importance of monitoring anxiety from the early stages of schooling in order to promote proficient academic performance

    The relation between cognitive and emotional factors and arithmetic problem-solving

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    Literature that investigates the factors underlying arithmetic problem-solving achievement extensively evaluates the cognitive components, such as Working Memory (WM) and Processing Speed, at the basis of this acquisition. Recently, studies have shown that also the emotional factors, such as Math Anxiety (MA), could play a crucial role in the resolution of arithmetic problem-solving even during the first years of formal education. In this study, we tested 145 fourth-grade students to evaluate the possible combined effect of cognitive (i.e., WM, Processing Speed) and emotional (i.e., Math Anxiety) factors in untimed arithmetical problem-solving achievement. Regression analysis showed that MA contributed significantly to explain arithmetic problem-solving achievement even after having accounted for the cognitive abilities (WM and Processing Speed). In addition, the comparison between high-MA and low-MA children showed that the former had decreased performance in arithmetical problem-solving and WM tasks. On the whole, data seemed to corroborate the findings concerning the crucial role of math anxiety on math achievement even in untimed math tasks. Findings are discussed in terms of math educational context and they underline the need to take into consideration also emotional factors\u2012 apart from the cognitive skills\u2012 when developing interventions on math achievement

    Immunization with antigenic extracts of Leishmania associated with Montanide ISA 763 adjuvant induces partial protection in BALB/c mice against Leishmania (Leishmania) amazonensis infection

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    Background/Purpose: A proper adjuvant has a relevant role in vaccine formulations to generate an effective immune response. In this study, total Leishmania antigen (TLA) formulated with Montanide ISA 763 or R848 as adjuvants were evaluated as a first generation Leishmania vaccine in a murine model. Methods: Immunization protocols were tested in BALB/c mice with a subcutaneous prime/boost regimen with an interval of 3 weeks. Mice immunized with unadjuvanted TLA and phosphate-buffered saline (PBS) served as control groups. On Day 21 and Day 36 of the protocol, we evaluated the humoral immune response induced by each formulation. Fifteen days after the boost, the immunized mice were challenged with 1 × 105 promastigotes of Leishmania (Leishmania) amazonensis in the right footpad (RFP). The progress of the infection was followed for 10 weeks; at the end of this period, histopathological studies were performed in the RFP. Results: Vaccines formulated with Montanide ISA 763 generated an increase in the production of immunoglobulin G (IgG; p < 0.05) compared with the control group. There were no statistically significant differences in IgG1 production between the study groups. However, immunization with TLA-Montanide ISA 763 resulted in an increase in IgG2a compared to the unadjuvanted control (p < 0.001). Also noteworthy was the fact that a significant reduction in swelling and histopathological damage of the RFP was recorded with the Montanide ISA 763 formulation. Conclusion: We conclude that the immunization of BALB/c mice with a vaccine formulated with TLA and Montanide ISA 763 generated a protective immune response against L. (L.) amazonensis, characterized by an intense production of IgG2a.Fil: Cargnelutti, Diego Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina. Universidad Nacional de Cuyo; ArgentinaFil: Salomón, María Cristina. Universidad Nacional de Cuyo; ArgentinaFil: Celedon, Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Garcia Bustos, Maria Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Patología Experimental. Universidad Nacional de Salta. Facultad de Ciencias de la Salud. Instituto de Patología Experimental; ArgentinaFil: Morea, Gastón. Universidad Nacional de Cuyo; ArgentinaFil: Cuello Carrión, Fernando Darío. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina. Universidad Nacional de Cuyo; ArgentinaFil: Scodeller, Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina. Universidad Nacional de Cuyo; Argentin

    Measurements with the ELI-NP cavity Beam Position Monitor Read-out Electronics at FLASH

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    The Extreme Light Infrastructure - Nuclear Physics Gamma Beam System (ELI-NP GBS) will be installed and commissioned starting within the next year in Magurele, Romania. It will generate gamma beam through Compton back-scattering of a recirculated laser and a multi-bunch electron beam, produced by a 720 MeV LINAC. In order to obtain bunch by bunch position measurements, four cavity beam position monitors (cBPM) near the two interaction points are foreseen. Extensive tests on the cBPM readout electronics, recently developed by Instrumentation Technologies and acquired for ELI-NP GBS, were performed in laboratory at INFN-LNF and at FLASH in DESY, during the user operation. In the latter case, three cBPMs installed along the LINAC, with similar features as the ones of ELI-NP GBS, were used as measuring devices and signal sources for the read-out electronics under test. We present here the measurements collected and the related analysis, with a particular focus on the beam position measurement resolution
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